FIG. 1A illustrates a terminal structure of a secondary battery and a structure of a bus bar which interconnects adjacent secondary batteries that are described in Patent Literature 1. The secondary battery 10 includes a main body 11 which houses a set of electrodes, positive and negative electrode terminals and a plate 12. FIG. 1A illustrates a cross-sectional structure of the positive electrode terminal 13. The positive electrode terminal 13 includes a connector part 14 and a positive electrode plate 15.
The connector part 14 includes a connector main body 14a, an opening 14b formed in the upper part of the connector main body 14a, and a projection 14c provided on a side surface of the opening 14b. The positive electrode plate 15 protrudes in the opening 14b of the connector main body 14a thorough an opening 12a provided in the plate 12. The negative electrode terminal has a structure similar to the positive electrode terminal 13 illustrated in FIG. 1A.
A mating connector part 22 is provided at each of the ends of the bus bar 20 which are spaced a given distance apart from each other with a main body 21 between them. The bus bar 20 includes the main body 21, the mating connector parts 22, openings 23 each provided at the lower end of a corresponding one of the mating connector parts 22, a conductor 24, wherein each of the mating connector parts 22 includes a bent part 25 which is a bent portion of the conductor 24 in the opening 23, a raised part 26 which is provided on an inner surface of the opening 23 and faces the bent part 25, and a recess 27 provided in a position corresponding to the projection 14c of the connector part 14.
FIG. 1B illustrates the secondary battery 10 and the bus bar 20 connected with each other. The mating connector parts 22 at the ends of the bus bar 20 are respectively inserted in the openings 14b of the connector parts 14 of the positive electrode terminal and the negative electrode terminal of adjacent secondary batteries. Like FIG. 1A, FIG. 1B illustrates the positive electrode terminal 13 side.
An end of the positive electrode plate 15 of the positive electrode terminal 13 contacts the bent part 25 and the raised part 26 of the mating connector part 22, and the projection 14c fits into the recess 27 of the mating connector part 22 to complete the connection.